Month: November 2017

Our highway and interstate system is a critical component of our nation’s infrastructure and economy. They are essential for the transportation of goods and services, emergency responders, commuting to work, and family vacations. It is imperative that our highways provide safe travel for all. Highway guardrails (see picture) are an important safety component of our highways. They typically consist of a galvanized metal rail, treated wood block, treated wood post, and fasters. However, steel blocks and posts can also be used.

Chromated copper arsenate (CCA) has a long history as an EPA approved wood preservative for numerous applications such as posts and blocks used in the guardrail assembly. Numerous independent studies have shown that CCA is an environmentally safe wood preservative and has very minimal leaching. Dr. Kenneth Brooks wrote in Pressure Treated Wooden Utility Poles and Our Environment that “pressure treated wood utility poles pose no greater risk to the environment than growing the wheat used to bake your next loaf of bread, and present far less personal risk than driving to your local grocery store to purchase that bread.” Similarly, Dr. Paul Morris has written “There are environmental risks associated with everything we do and with all of the material used to construct utility structures. For instance, the leaching of zinc from steel utility poles.”

Reuse of treated wood highway guard rail posts for energy recovery will offset the use of fossil fuel energy and thereby reduce greenhouse gas levels in the atmosphere.

Bottom Line

CCA-treated wood is a critical part of our nation’s infrastructure and economy. It is safe for the environment and has a long history of EPA approval for both the environment and human exposure. The alternatives (steel and concrete) are not renewable and require more energy to produce than CCA-treated wood. Last but not least, CCA-treated wood is more cost effective than the alternatives. CCA-treated wood is good for the environment and the economy!

Our society has become much more environmentally sensitive and responsible in recent years. Recycling has increased, air and water standards are improved, smoking tobacco is generally prohibited inside most public buildings, etc. However, a phobia exists regarding wooden poles. There is nothing particularly aesthetically appealing about a creosote-treated pole that is leaching creosote out onto the adjacent sidewalk as I witnessed today. However, wooden poles are good for the environment and much better than the alternatives.

Wooden poles are visible along almost every city street and rural highway. They are essential components of our national infrastructure. They are impregnated with chemicals that must be toxic to stop degradation from insects and fungi. Yes, some of these preservatives will leach out into the adjacent soil. However, wood utility poles are much kinder to our planet than other materials. Independent, science-based life cycle assessments, or LCAs, confirm that preserved wood utility poles use less energy and resources, offset fossil fuel use and have a reduced environmental impact when compared to concrete, steel and fiber-reinforced composite utility poles.

Wood poles are made from a plentiful and renewable resource grown on managed timberlands. Growing trees produces oxygen and when converted into a product, wood stores carbon. Wood poles also help limit the accumulation of greenhouse gases. Due to the insulating properties of wood, eagles, ospreys and other large birds are able to perch on wood crossarms without danger of electrocution.

Dr. Kenneth Brooks dedicated much of his career to studying the environmental impacts of preservative-treated wood poles. Some of the key findings of his research are: (1) pressure treated wood utility poles pose no greater risk to the environment than growing the wheat used to bake your next loaf of bread, and present far less personal risk than driving to your local grocery store to purchase that bread. (2) there are environmental risks associated with everything we do and with all of the material used to construct utility structures. For instance, the leaching of zinc from steel utility poles has been documented. (3) Utility poles are not continually immersed in water and the actual lifetime losses are likely far lower — perhaps the equivalent of a penny of copper per year for each 20 poles. “